Electronic timepiece calendar circuit

Abstract

An electronic timepiece calendar circuit whereby the display of at least the date is automatically effected during both leap years and non-leap years is provided. The electronic timepiece calendar circuitry includes a date counter that is indexed by a count of one from a count of one to at least 31 and thereafter is returned to a count of one to begin counting the dates of the next month. A month counter is provided for being indexed by one through a count of one to at least 12 each time the date counter is returned to a count of one and further is adapted to produce a signal representative of the count thereof. A control circuit is provided for receiving the month signal produced by the month counter and in response thereto returns the count of the day counter to one when the count of the month counter is two and the date counter is changed from 28 to 29 or from 30 to 31 depending on whether a leap year signal is applied thereto. The leap year signal is produced by year circuitry including a first year counter adapted to be indexed through a counting cycle of one to nine and a ten year counter series connected to the year counter that is adapted to be indexed through at least one odd and even counting cycle in response to each return of the month counter to a count of zero. A judging circuit is provided for detecting when the count of the year counter is zero, four and eight and the count of the 10 year counter is even, or alternatively, when the count of the year counter is two or six and the count of the 10 year counter is odd, and in response to detecting either alternative, applying a leap year signal to the control circuit.

What is claimed is: 
     
       1. In an electronic timepiece having year counter means for producing a signal representative of a leap year and including date counter means adapted to receive a clock pulse having a period of one-day and in response to each said clock pulse received thereby, said date counter means being indexed through a counting cycle from one to at least 31 to thereby produce a date signal representative of the count thereof, and a month counter means for detecting each return of the date counter to a count of one and in response thereto being indexed by a count of one through a counting cycle from one to at least 12 and thereby produce a month signal representative of the count thereof, and control means for receiving said month signal and day signal and when said month signal is representative of a count of two, said control means, in the absence of a leap year signal applied thereto, being adapted to return the date counter means to a count of one in response to detecting when the count of the day counter is changed from 28 to 29, said control means being further adapted, in response to the presence of a leap year signal applied thereto to return the count of the day counter means to one when the count of the date counter means is changed from 29 to 30, the improvement comprising said year counter means including a year counter adapted to be indexed by a count of one through a counting cycle from zero to nine and thereby produce a year signal representative thereof, and a 10-year counter series connected to said year counter for being cycled at least through one odd and one even counting cycle in response to each return of the count of the year counter to zero, and producing a 10-year signal representative of the count thereof, and judging circuit means for receiving said year counting signal and said 10-year counting signal, and in response to detecting one of the year signals having one of a count of zero, four and eight and said 10-year signal having an even count, and the year signal having one of a count of two and six and the 10-year signal having an odd count, applying a leap year signal to said control means. 
     
     
       2. An electronic timepiece as claimed in claim 1, wherein said judging circuit means includes a first gate means coupled to said year counter and to said 10-year counter, and a second gate means coupled to said year counter and 10-year counter, said first gate means being adapted to produce said leap year signal when said 10-year counter produces a signal having an even count, said second gating means being adapted to produce a leap year signal when said 10-year counter produces a 10-year signal having an odd count. 
     
     
       3. An electronic timepiece as claimed in claim 2, and including reset means coupled to said 10-year counter for detecting when the count of same is indexed through at least one even and one odd counting cycle, and in response thereto being adapted to apply a reset signal to said year counter and 10-year counter to thereby reset the count of the year counter to zero and the count of the 10-year counter to one of a predetermined odd and even count. 
     
     
       4. An electronic timepiece as claimed in claim 3, wherein said control means includes date circuit judging means coupled to said date counter means, said date circuit judging means being adapted to apply a reset signal to said date counter means in response to detecting the count of said date counter means being indexed from a count of 31 to a count of 32, to thereby reset the count of the date circuit means to a count of one. 
     
     
       5. An electronic timepiece as claimed in claim 4, and wherein said control means includes month judging means adapted to detect when the count of the month counter is indexed from a count 12 to a count of 13, and in response thereto, apply a reset signal to said month counter means to reset the count thereof to a count of one. 
     
     
       6. An electronic timepiece as claimed in claim 5, wherein said month circuit judging means further includes means for detecting when the count of said month counter is one of a count of four, six, nine and eleven and in response thereto is adapted to apply a 30-day month signal to said date circuit judging means, said month circuit judging means being further adapted to detect when the count of said month counter means is indexed to a count of two and in response thereto apply a less than 30-day month signal to said date circuit judging means, said date circuit judging means having a 30-day judging circuit means adapted to receive said 30-day signal and detect when the count of said date counter means is indexed from a count of 30 to a count of 31, and in response thereto apply a reset signal to said date counter means to reset the count of same to one, said date circuit judging means further including February detecting means for detecting said less than thirty-day signal, and in the absence of a leap year signal applied thereto, being adapted to apply a reset signal to said date counter means in response to detecting the count of said date counter means being indexed from a count of 28 to a count of 29. 
     
     
       7. An electronic timepiece as claimed in claim 6, and including gate means disposed intermediate said date circuit judging means and said month counter means, said gate means being adapted to gate said reset signal to said month counter means when same is applied to reset said date counter means, and thereby index the count of said month counter means by a count of one, and second gate means disposed intermediate said month circuit judging means and said year counter, for gating said reset signal to said year counter and thereby index same by a count of one in response to the reset signal being applied to the month counter means to reset the count thereof to one. 
     
     
       8. An electronic timepiece as claimed in claim 7, and including a third gate means adapted to receive said clock pulse having a period of one-day and effect gating of same to the input of said date counter means to index the count of said date counter means by a count of one in response to each clock pulse applied thereto. 
     
     
       9. An electronic timepiece as claimed in claim 8, wherein each of said first, second and third gate means includes as a second input, a gating signal, said gating signal being adapted to inhibit the application of a signal to the respective counter means to which same is coupled during correction of the counters. 
     
     
       10. An electronic timepiece as claimed in claim 2, wherein said timepiece includes an hours, minutes and seconds counter for producing timekeeping signals representative of hours, minutes and seconds, display means for displaying one of a time-keeping display in response to said timekeeping signals being applied thereto and a calendar display in response to the signals produced by the date, month and year counter means being applied thereto, and selector means disposed intermediate said timekeeping display means and calendar display means for selectively applying one of said timekeeping signals and calendar display signals to said display means. 
     
     
       11. An electronic timepiece as claimed in claim 10, wherein said digital display means includes flicker means, said flicker means being adapted to selectively flicker predetermined digits of time displayed when the timepiece is disposed in a time-keeping mode by the selector circuit applying timekeeping signals to the digital display means, and flickering calendar digits to be corrected when the timepiece is in a calendar display mode in response to the selector circuit applying calendar signals to said digital display means. 
     
     
       12. An electronic timepiece as claimed in claim 11, and including control circuit means coupled to said hours, minutes and seconds counter means and to said day, month and year counter means, said control circuit means being further coupled to said selector means and said flicker circuit means, and three manually operated switch means coupled to said control circuit means, said first manually operated switch means, being adapted to select one of a locked condition and an unlocked condition, said locked condition preventing correction of the count of said hours, minutes and seconds counter means and said day, month and year counter means, said second manually operated switch means being adapted to select between a calendar display mode and a timekeeping display mode when said first manually operated switch means is in a locked condition. 
     
     
       13. An electronic timepiece as claimed in claim 12, wherein said flicker circuit means is energized in response to said first manually operated switch being disposed in an unlocked position, said flicker circuit being adapted to be indexed by a count of one in response to each actuation of said second manually operated switch when said first manually operated switch means is in an unlocked condition, and thereby effect flickering of a different hours, minutes and seconds counter and day, month and year counter having the time counted thereby being displayed. 
     
     
       14. An electronic timepiece as claimed in claim 13, wherein said third manually operated switch means is adapted to index the count of said counter having the count thereof flickered, to thereby advance the count thereof by a count of one.